In today's vehicles, the drive power of a vehicle is normally regulated by the accelerator pedal, whereby in modern vehicles, the connection between the accelerator pedal position and the engine load is generally no longer made by a direct mechanical coupling. As a rule, an electronic engine control unit regulates the engine load, taking various parameters into consideration such as, for example, the accelerator pedal position. When the accelerator pedal is continuously actuated starting from the zero position, the drive torque of an engine is continuously increased accordingly in that the control element responsible for the drive, e.g. the throttle valve in Otto engines, is actuated. In the zero position itself, no drive torque is transmitted, that is to say, the engine goes into overrun fuel cutoff operation, which results in so-called motoring reverse torque. With many of the modern accelerator pedal configurations, it is only possible to effectuate drive power via the engine, or to go to overrun fuel cutoff with the engine. The transition from one operating state to the other is abrupt and cannot be dosed.
German Preliminary Published Application DE 199 22 338 A1 describes a method for the production of a prescribed effective relationship between the actuation of the accelerator pedal and the resulting braking torque of a vehicle, whereby the possible adjustment range of the accelerator pedal is divided into at least two control ranges. A first control range is defined below a first prescribed angle of the accelerator pedal. In the first control range, actuators that can bring about a deceleration of the vehicle are regulated on the basis of a prescribed course of the braking torque. Preferably, the second control range is defined above a second prescribed angle of the accelerator pedal. Between the first and the second prescribed accelerator pedal angles, a third control range is defined in which the actuators, which can bring about a deceleration or an acceleration, are regulated in such a way that the braking torque or the drive torque of the vehicle is kept constant.
U.S. Pat. No. 7,188,546 B2 discloses an accelerator pedal unit for a vehicle, comprising an accelerator pedal that is functionally connected to a vehicle drive means, whereby the vehicle also has a separate brake pedal that is functionally connected to a vehicle braking means. When the accelerator pedal is moved out of an idle position into a driving position, the vehicle is caused to progressively increase the magnitude of the driving force. Here, the accelerator pedal is configured to operate over a predetermined pedal travel which spans from a resting position to the idle position and through to a driving position. Moreover, the accelerator pedal is functionally connected to the vehicle braking means, whereby the braking means causes the vehicle to progressively increase the magnitude of a braking force that is exerted on the vehicle when the accelerator pedal moves from the idle position to a resting position, whereby the braking means physically moves the brake pedal to a specific position that corresponds to the braking force exerted by the accelerator pedal unit, whereby the accelerator pedal is biased towards the resting position.
International patent application WO 2009/023916 A2 describes an accelerator pedal system and braking system for a vehicle, whereby the braking system responds to forces exerted on the accelerator pedal, whereby data that corresponds to the force exerted on the accelerator pedal is relayed to a control module, and whereby the braking force is influenced by the force exerted on the accelerator pedal.
In all of the systems described in the state of the art, an accelerator pedal position can be selected in which the engine exerts neither a drive torque nor a braking torque on the vehicle. However, this accelerator pedal position changes as the vehicle speed changes due to, for instance, the vehicle coasting, so that the driver would constantly have to readjust the accelerator pedal position in order to achieve an optimal energy utilization involving the lowest possible fuel consumption.